The magnetic-recording, hard-disk-drive (HDD) industry is extremely competitive. The demands of the market for ever increasing storage capacity, storage speed, and other enhancement features compounded with the desire for low cost creates tremendous pressure for improved HDDs. Therefore, scientists at the frontiers of magnetic-recording technology are driven to improve methods of information retrieval and storage in HDDs. One such method is perpendicular-magnetic-recording (PMR).
However, PMR, as all innovative technological advances, is fraught with both pit falls and opportunities. The higher recording densities brought within reach by PMR has been accompanied by increased demands on the control of the scaled-down dimensional tolerances between the PMR head and the PMR disk, on which information is stored and from which information is retrieved. Thus, it is of paramount importance to effectively and reliably control the spacing between the PMR head and the PMR disk. Scientists engaged in the advance of PMR technology are focused on improving the control of this critical spacing between the PMR head and the PMR disk.